1. Field of the Invention
This invention relates to novel guanidine derivatives and fungicides for agriculture and horticulture containing said derivatives as an active ingredient.
2. Description of the Prior Art
Some of the literatures disclose guanidines. For example, Japanese Patent Publication No. 29742/1968 discloses a process for preparing substituted guanidines represented by the formula ##STR1## wherein R'.sub.1 represents a substituted or unsubstituted aromatic hydrocarbon residue and R'.sub.2 or R'.sub.3 represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon residue.
There are also disclosed in Japanese Patent Publication No. 9846/1975 guanidines represented by the formula ##STR2## wherein X'.sub.1 represents a hydrogen atom or a chlorine atom and R'.sub.4 represents a benzylamino group or the like which have insecticidal and acaricidal activities as well as plant disease controlling activity.
Although the known guanidines have some fungicidal activities for agriculture and horticulture, they have not been put into practical use due to their not satisfactorily high activities and their phytotoxicities. On the other hand, serious diseases of fruit trees, vegetables or cereals such as mildew, blight, powdery mildew and rust have hitherto been treated with various chemicals, all of which are unusable or of restricted use due to resistance to the chemicals. Therefore, development of novel fungicides different in skelton structure from prior-art chemicals has become a big problem in these fields.